Combined centralizer and retainer for rock-drill steels



May 12,1925.

\ v c. c. HANSEN COMBINED CENTRALIZER AND RETAINER FOR ROCK DRILL STEELS 2 Sheets-Sheet 1 .r f. T

Filed May 24 1924 :IIIII llll r lll-lllll INVENTOR Y lzaa'leaflflansc n;

Hi5 ATTOR Y May 12', 1925.

C. C. HANSEN COMBINED CENTRALIZER AND RETAINER FOR ROCK DRILL STEELS Filed May 24, 1924 2 Sheets-Sheet 2 INVENTOR v aides flflansen Patented May 12, 192 5.

UNITED STATES PATENT OFFICE.

CHARLES C HANSEN, O'F EASTON, PENNSYLVANIA,

ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, JERSEY, A CORPORATION OF NEW JERSEY.

COMBINED CENTRALIZER AND ROCK-DRILL STEELS.

Application filed ma 24, 1924. Serial No. 715,717.

To all whom it may concern:

Be it known that I, CHARLES C. HANSEN, a citizen of the United States, and a resident of Easton, county of Northampton, and State of Pennsylvania, have invented a certain Combined Centralizer and Retainer for Rock-Drill Steels, of which the following is a specification, accompanied by drawings.

This invention relates to rock drills, and more particularly to rock drill steel retainers and centralizers, one of the objects of the invention being to combine in a single structure, the functions of centralizing and retaining a steel within the drill.

The invention contemplates the use of either round, hexagon or other forms of drill steels including flat broaching steels, all of these adapted to be used in the same device. In the case of broaching steels the steel holder is adapted to prevent rotation. Still another object of the invention is to support the centralizer from the fore-part of the drill employing parts which are usually to be found in rock drills such as the through bolts and through bolt springs for holding the front head yieldingly on the cylinder. In the preferred embodiment of the invention the retainer and centralizer is also held yieldingly on the front head by means of the through bolts and through bolt springs, but with suiiicient rigidity to insure proper d irectioning of the steel.

A still further object of the invention is to permit the removal with very little difliculty of the steel from the drill.

A device of this character is more particularly adapted for that style of drilling own as broaching, wherein a plurality of holes are drilled in line and at very accurate spacing. In such work the material between the spaced holes is broken away by a broaching steel which must be held or centralized accurately to be directed at the rock between the holes and at the same time be held against rotation and deflection. It is equally necessary that the round holes first drllled be parallel and to this end the drill must be centralized and guided to prevent'the holes from running into each other, thereby leaving adjacent thick walls to be broken down by the broaching steel. This condition is bad for the reason that broaching steel is adapted to crush and break the rock in comparatively large chips rather than to drill in the usual sense of the term.

A preferred embodiment of the invention is hereinafter described in conjunction with the drawings, in which Figure l isa vertical'elevation partly in sectlon of a centralizer and retainer constructed in accordance with the practice of the invention and mounted on the forward part of a drill,

Figure 2 is a section of a portion of the supporting means for the centralizer taken along the line 2-2 looking in the direction of the arrows,

Figure 3 is a section of the centralizer taken. along the line 33 looking in the direction of the arrows,

Figure 4 is a front elevation of a part of the centralizer showing the manner in which a fiat broaching steel is held thereby.

Figure 5 is a perspective view of a guide member forming part of the centralizer, and

Fi ure 6 is a perspective view of a part comp ementary to the guide member shown in Figure 5, which is removable therefrom to permit withdrawal of the steel.

The drawings illustrate the combined centralizer and steel retainer in position on the front head of a rock drill which, as shown, includes a front head A provided with ears B reinforced with webs pockets D into which the through bolts E project. The through bolts E are provided with through bolt springs F fitting in the pockets D to absorb the shock of the hammer piston (not shown) as it strikes against the front head A. o

The retainer comprises a pair of for- C forming G yieldingly supported on the front head A as by means of the blocks H which are provided with holes {I to fit the through bolts E accurately under the through bolt springs F. The blocks H are provided with other apertures K preferably fitted to rigidly hold the bolts G and additionally to adjust said bolts as to length. Lock nuts L are provided on the bolts G to maintain their ad justment.

On the forward end of the bolts G is mounted a guide 0 held in place thereon by the nuts P and Q. As shown inFigure adapted to lie flat on the face S of the guide and to be held partly by the guide against rotation. At either side of the guideO adjacent the bolts G there are tapered slots T which are adapted to cooperate with tapered ends U of a guide plate V which is formed as at W also to fit either round, hexagon or flat broaching steels in cooperation with the face S. The ta er of the ends U of the .guide plate V and t e slots T is preferably such that when the guide plate V is tapped into place it will stay in place b friction. If desired, however, a retainer rotatable on one of the bolts G and held in place by the tension of a coil spring Y may be used to brace against the upper side of the guide plate V to hold the latter in place. A lever or handle Z may be provided'on the retainer X to assist in lifting the retainer against the tension of the coil spring Y.

The operation of the device is clear from the above description, it being noted that when it is desired to insert a steel, as for instance, the hexagonal drill steel a shown in Figure 1, the guide plate V having been removed, the steel is inserted into the chuck b in the front head A of the drill until the steel collar 0 is between the front head A and the guide 0 and preferably against'the end of the chuck b. In this position the guide plate V is inserted in the slots T of the guide 0 and tapped to make it secure. The collar 0 cannot then pass the guide 0 or guide plate V since the aperture between the recesses R and W does not permit. Also, this aperture is sufiiciently small to fit rather closely about the drill steel so that the latter is centralized.

This function, is extremely useful as has been said before in drilling a series of holes as shown at d at accurately spaced intervals in quarrying operations where stone is cut out rather than blasted. A series of such holes d are drilled and later connected by chop ing out, as it were, the material between t e holes by means of a broaching steel as shown at e, Fi ure 4:. It

is uite desirable that a broac ing steel be eld against rotation as well as being firmly held against side movement. The rectangular a erture 7 formed by the face S of the gui e O and the recess W of the guide plate V prevents the side motion and counteracts the tendency of the steel e to rotate. Even though the drill be held firmly in its mounting, the chuck b or the shanks of the steels a may become worn or loose so that it is practically impossible to direct the steels without a centralizer. Drill steel centralizers have been heretofore employed for certain types of work especially for starting holes, but in the main such centralshock due to the hitting of the collar 0 against the guide 0 is absorbed\ without damage to the retainer by the through bolt springs F which are very powerful and adapted to this type of service.

I claim:

1. A combined centralizer and retainer for rock drill steels comprising a pair of forwardly extending members adapted to be supported on the front head of a rock drill, a slotted guide mounted forwardly on said members and formed to receive a drill steel and to limit its forwardmotion, and a guide plate insertable in the slotted guide and" partly encircling. said steel.

2. A combined centralizer and retainer for rock drill steels comprising a pair ofv forwardly extending members adapted to be supported on the'front head of a rock drill, a guide provided with tapered slots mounted forwardly on said members and formed to receive a drill steel and to limit its forward motion, and a guide plate shaped with said guide to encircle the drill steel and having tapered edges cooperative with the slots in said ide to be held in position in the guide t ereby.

3. A combined centralizer and retainer for rock drill steels comprising a pair of blocks adapted to be held yieldlngly under the through bolt springs of a rock drill, a pair of forwardly extending bolts mounted on sa1d blocks, a slotted guide mounted on the forward ends of said bolts formed to receive a drill steel and .to limit its forward motion, and a guide plate insertable in said slotted guide and shaped with said guide to encircle the drill steel.

4. A combined centralizer and retainer for rock drill steels comprising a pair of blocks adapted to be held yieldin y under the through bolt springs of a rodlrdrill, a pair of forwardly extending bolts mounted on said blocks, a uide mounted on the forward ends of sai bolts provided with tapered slots and formed to receive a drill steel and to limit its forward motion, and a guide plate having tapered sides cooperating" with said tapereds'lots to .hold said and to limit its forward motion, and a guide plate insertable in the guide and partly encircling said steel.

6. A combined centralizer and retainer for rock drill steels comprising a pair of 5 forwardly extending members adapted to be yieldingly supported on the front head of :1 rock drill, a guide mounted forwardly on said members adapted to receive the steel and to limit its forward motion, and a guide plate insertable in the guide and 10 partly encircling said steel.

In testimony whereof I have signed this specification.

CHARLES C. HANSEN. 

